Preparation of materials involved in supramolecular chemistry: graphene film

Recently, the top international journal Nature released the list of "top ten people of 2018" Cao Yuan, a Chinese student who is studying for a Ph.D in MIT in the United States, topped the list His research on graphene has made this promising material more widely used In recent years, some scholars have developed a similar material, graphene (GDY), on the basis of graphene nanomaterials Graphene contains only SP 2 hybrid carbon atoms Different from it, graphene has SP and SP 2 hybrid carbon atoms at the same time, and it has rich carbon chemical bonds, large conjugation system, wide surface spacing and excellent chemical stability Therefore, graphene is known as a stable allotrope of synthetic carbon diyne However, although there are many methods to prepare various kinds of graphene materials, the preparation of high-quality graphene films still faces many difficulties Figure 1 Preparation of graphene materials based on Supramolecular Chemistry (photo source: J am Chem SOC.) recently, Academician Li Yuliang and researcher Li Yongjun from the Key Laboratory of Chemical Research Institute of the Chinese Academy of Sciences reported a preparation method of benzenesubstituted graphene (Ben GDY), a graphene analogue The team introduced some concepts of supramolecular chemistry in the synthesis process Through π - π interaction and CH ·· π interaction, the author successfully inhibited the rotation of Ben GDY monomer (3), and then prepared high crystallinity graphene film (Fig 1b) This achievement was published in the Journal of the American Chemical Society (DOI: 10.1021 / JACS 8b09945) under the title of "direct synthesis of crystal graphdiyne analogue based on on supramolecular interactions" The corresponding author of this paper is researcher Li Yongjun Fig 2 Preparation diagram of Ben GDY monomer and film (photo source: J am Chem SOC.) Ben GDY film is obtained by coupling reaction of monomer 3 in the presence of catalyst The preparation method of 3 is relatively simple, as shown in Fig 2, the triphenylsubstituted benzene derivative 1 is coupled with phenylboronic acid to obtain triphenylsubstituted benzene derivative 2 through Suzuki coupling reaction; after that, 2 removes the protective group on the alkynyl group to obtain graphite alkyne precursor 3 After the preparation of 3, the author used copper foil as the substrate and carried out the coupling reaction on the surface of copper foil in a similar way of layer by layer self-assembly to obtain the Ben GDY film (Fig 2) Figure 3 Structure characterization of Ben GDY film (photo source: J am Chem SOC.) in order to prove that the prepared film is obtained by 3-reaction, the author has carried out a series of structural characterization of the film The UV-Vis spectrum shows that the UV absorption of the film obtained by coupling has a great red shift compared with that of monomer 3 (Fig 3C) The author speculates that this is due to the increase of the electron delocalization effect caused by the increase of the conjugated system, which also reflects the success of the coupling reaction from the side XPS shows that the film contains not only carbon, but also SP 2 and SP hybrid C-C bond (Fig 3a) In addition, the signal at 2192 cm-1 in Raman spectrum (the characteristic peak of carbon carbon triple bond in butynedyne) shows that the Ben GDY film is indeed obtained by coupling 3 (Fig 3b) Figure 4 Morphology characterization of Ben GDY film (photo source: J am Chem SOC.) next, the author further characterized the morphology of Ben GDY film AFM (FIG 4A) and SEM (Fig 4b) images show that the prepared materials do have film structure and the thickness is about 30 nm Combining the results of TEM (Fig 4C), HRTEM (Fig 4D), stem (Fig 4e) and saed (Fig 4F), the author is sure that the prepared films have very high crystallinity Highlight: the author innovatively introduced the concept of supramolecular chemistry into the synthesis of graphene film, and obtained the high crystallinity graphene film Ben GDY by this method Full text author: Weixiang Zhou, Han Shen, Chenyu Wu, Zeyi Tu, Feng He, Yanan Gu, Yurui Xue, Yingjie Zhao, Yuanping Yi, Yongjun Li, and Yuliang Li